Add four_byte_interp benches.

Desktop:
running bench [640 480] four_byte_interp_slow_256    NONRENDERING: cmsecs =      6.18
running bench [640 480] four_byte_interp_slow_255    NONRENDERING: cmsecs =      6.83
running bench [640 480] four_byte_interp_fast_256    NONRENDERING: cmsecs =      5.02
running bench [640 480] four_byte_interp_fast_255    NONRENDERING: cmsecs =      5.88

N5:
running bench [640 480] four_byte_interp_slow_256    NONRENDERING: cmsecs =     22.84
running bench [640 480] four_byte_interp_slow_255    NONRENDERING: cmsecs =     25.11
running bench [640 480] four_byte_interp_fast_256    NONRENDERING: cmsecs =     18.89
running bench [640 480] four_byte_interp_fast_255    NONRENDERING: cmsecs =     22.32

BUG=
R=reed@google.com

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/93933003

git-svn-id: http://skia.googlecode.com/svn/trunk@12444 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 56 insertions, 0 deletions

diff --git a/bench/ColorPrivBench.cpp b/bench/ColorPrivBench.cpp
new file mode 100644
index 0000000000..3143ef4525
--- /dev/null
+++ b/bench/ColorPrivBench.cpp
@@ -0,0 +1,56 @@
+#include "SkBenchmark.h"
+#include "SkColorPriv.h"
+#include "SkRandom.h"
+#include "SkString.h"
+
+template <bool kFast, bool kScale>
+class FourByteInterpBench : public SkBenchmark {
+public:
+    FourByteInterpBench() {
+        fName.set("four_byte_interp");
+        fName.append(kFast ? "_fast" : "_slow");
+        fName.append(kScale ? "_255" : "_256");
+
+        // We'll exhaustively test all scales instead of using random numbers.
+        for (int i = 0; i <= 256; i++) {
+            fScales[i] = i;
+        }
+        if (kScale) fScales[256] = 255;  // We'll just do 255 twice if we're limited to [0,255].
+    }
+
+    virtual bool isSuitableFor(Backend backend) SK_OVERRIDE {
+        return backend == kNonRendering_Backend;
+    }
+
+    virtual const char* onGetName() SK_OVERRIDE { return fName.c_str(); }
+
+    virtual void onDraw(SkCanvas*) SK_OVERRIDE {
+        const SkPMColor src = 0xAB998877, dst = 0x66334455;
+        volatile SkPMColor junk = 0;
+        for (int i = 0; i < 10*this->getLoops(); ++i) {
+            for (size_t j = 0; j <= SK_ARRAY_COUNT(fScales); j++) {
+                const unsigned scale = fScales[j];
+                if (kFast && kScale) {
+                    junk ^= SkFastFourByteInterp(src, dst, scale);
+                } else if (kFast) {
+                    junk ^= SkFastFourByteInterp256(src, dst, scale);
+                } else if (kScale) {
+                    junk ^= SkFourByteInterp(src, dst, scale);
+                } else {
+                    junk ^= SkFourByteInterp256(src, dst, scale);
+                }
+            }
+        }
+    }
+
+private:
+    SkString fName;
+    unsigned fScales[257];  // We need space for [0, 256].
+};
+
+#define COMMA ,
+DEF_BENCH( return SkNEW(FourByteInterpBench<true COMMA true>); )
+DEF_BENCH( return SkNEW(FourByteInterpBench<true COMMA false>); )
+DEF_BENCH( return SkNEW(FourByteInterpBench<false COMMA true>); )
+DEF_BENCH( return SkNEW(FourByteInterpBench<false COMMA false>); )
+#undef COMMA